Aim: To test the extent to which the vertical structure of tropical forests is determined by environment, forest structure or biogeographical history. Location: Pan-tropical. Methods: Using height ...and diameter data from 20,497 trees in 112 non-contiguous plots, asymptotic maximum height (H AM ) and height—diameter relationships were computed with nonlinear mixed effects (NLME) models to: (1) test for environmental and structural causes of differences among plots, and (2) test if there were continental differences once environment and structure were accounted for; persistence of differences may imply the importance of biogeography for vertical forest structure. NLME analyses for floristic subsets of data (only/excluding Fabaceae and only/excluding Dipterocarpaceae individuals) were used to examine whether family-level patterns revealed biogeographical explanations of cross-continental differences. Results: H AM and allometry were significantly different amongst continents. H AM was greatest in Asian forests (58.3 ± 7.5 m, 95% CI), followed by forests in Africa (45.1 ± 2.6 m), America (35.8 ± 6.0 m) and Australia (35.0 ± 7.4 m), and height—diameter relationships varied similarly; for a given diameter, stems were tallest in Asia, followed by Africa, America and Australia. Precipitation seasonality, basal area, stem density, solar radiation and wood density each explained some variation in allometry and H AM yet continental differences persisted even after these were accounted for. Analyses using floristic subsets showed that significant continental differences in H AM and allometry persisted in all cases. Main conclusions: Tree allometry and maximum height are altered by environmental conditions, forest structure and wood density. Yet, even after accounting for these, tropical forest architecture varies significantly from continent to continent. The greater stature of tropical forests in Asia is not directly determined by the dominance of the family Dipterocarpaceae, as on average non-dipterocarps are equally tall. We hypothesise that dominant large-statured families create conditions in which only tall species can compete, thus perpetuating a forest dominated by tall individuals from diverse families.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
This study compares the organic chemistry of peat beneath one of last remaining pristine tropical peat forests in Southeast Asia with a neighbouring peat dome that has been deforested, but not ...intentionally drained, in the Belait district of Brunei Darussalam, Borneo. We characterized the solid and dissolved organic matter collected from the two domes, through a combination of methods including elemental analysis, phenolic content and Fourier transform infrared spectroscopy (FTIR) investigation of solid peat, as well as optical characterisation (absorbance, fluorescence) of dissolved organic matter (DOM). The peat had a high content of lignin, consistent with its origin from the Shorea albida trees on the domes. Dissolved organic carbon (DOC) concentration in the pore water was significantly greater in the deforested site (79.9 ± 5.5 mg l⁻¹) than the pristine site (62.2 ± 2.2 mg l⁻¹). The dissolved organic matter was richer in nitrogen and phenolics in the deforested site. The optical properties (Fluorescence Index) indicated a modification of DOM cycling in the deforested site (enhanced decomposition of the peat and fresh litter). Comparison of the solid peat composition between the two sites also suggests effects of deforestation: sulphur, nitrogen and phenolic contents were higher in the deforested site. Taken together, these observations are consistent with peat enhanced decomposition in the deforested site, even without engineered drainage.
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BFBNIB, DOBA, EMUNI, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK
On Katugampola Fourier Transform Salim, Tariq O.; Abu Hany, Atta A. K.; El-Khatib, Mohammed S.
Journal of Mathematics,
2019, Volume:
2019
Journal Article
Peer reviewed
Open access
The aim of this article is to introduce a new definition for the Fourier transform. This new definition will be considered as one of the generalizations of the usual (classical) Fourier transform. We ...employ the new Katugampola derivative to obtain some properties of the Katugampola Fourier transform and find the relation between the Katugampola Fourier transform and the usual Fourier transform. The inversion formula and the convolution theorem for the Katugampola Fourier transform are considered.
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Global change is impacting forests worldwide, threatening biodiversity and ecosystem services including climate regulation. Understanding how forests respond is critical to forest conservation and ...climate protection. This review describes an international network of 59 long‐term forest dynamics research sites (CTFS‐ForestGEO) useful for characterizing forest responses to global change. Within very large plots (median size 25 ha), all stems ≥1 cm diameter are identified to species, mapped, and regularly recensused according to standardized protocols. CTFS‐ForestGEO spans 25°S–61°N latitude, is generally representative of the range of bioclimatic, edaphic, and topographic conditions experienced by forests worldwide, and is the only forest monitoring network that applies a standardized protocol to each of the world's major forest biomes. Supplementary standardized measurements at subsets of the sites provide additional information on plants, animals, and ecosystem and environmental variables. CTFS‐ForestGEO sites are experiencing multifaceted anthropogenic global change pressures including warming (average 0.61 °C), changes in precipitation (up to ±30% change), atmospheric deposition of nitrogen and sulfur compounds (up to 3.8 g N m⁻² yr⁻¹and 3.1 g S m⁻² yr⁻¹), and forest fragmentation in the surrounding landscape (up to 88% reduced tree cover within 5 km). The broad suite of measurements made at CTFS‐ForestGEO sites makes it possible to investigate the complex ways in which global change is impacting forest dynamics. Ongoing research across the CTFS‐ForestGEO network is yielding insights into how and why the forests are changing, and continued monitoring will provide vital contributions to understanding worldwide forest diversity and dynamics in an era of global change.
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Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across ...four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: 1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass? 2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots? 3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates? The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (≤40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg ha−1 (range 6.6 to 112.4) to 8.0 Mg ha−1 (−2.5 to 23.0). For all plots, aboveground live biomass was −52.2 Mg ha−1 (−82.0 to −20.3 bootstrapped 95% CI), or 13%, lower when including H estimates, with the greatest relative reductions in estimated biomass in forests of the Brazilian Shield, east Africa, and Australia, and relatively little change in the Guiana Shield, central Africa and southeast Asia. Appreciably different stand structure was observed among regions across the tropical continents, with some storing significantly more biomass in small diameter stems, which affects selection of the best height models to reduce uncertainty and biomass reductions due to H. After accounting for variation in H, total biomass per hectare is greatest in Australia, the Guiana Shield, Asia, central and east Africa, and lowest in east-central Amazonia, W. Africa, W. Amazonia, and the Brazilian Shield (descending order). Thus, if tropical forests span 1668 million km2 and store 285 Pg C (estimate including H), then applying our regional relationships implies that carbon storage is overestimated by 35 Pg C (31–39 bootstrapped 95% CI) if H is ignored, assuming that the sampled plots are an unbiased statistical representation of all tropical forest in terms of biomass and height factors. Our results show that tree H is an important allometric factor that needs to be included in future forest biomass estimates to reduce error in estimates of tropical carbon stocks and emissions due to deforestation.
The highest financial and symptom burdens and the lowest health-related quality-of-life scores are seen in people with kidney failure. A total of 11 countries in the International Society of ...Nephrology (ISN) Middle East region responded to the ISN-Global Kidney Health Atlas. The prevalence of chronic kidney disease (CKD) in the region ranged from 4.9% in Yemen to 12.2% in Lebanon, whereas prevalence of kidney failure treated with dialysis or transplantation ranged from 152 per million population (pmp) in the United Arab Emirates to 869 pmp in Kuwait. Overall, the incidence of kidney transplantation was highest in Saudi Arabia (20.2 pmp) and was lowest in Oman (2.2 pmp). Chronic hemodialysis (HD) and peritoneal dialysis (PD) services were available in all countries, whereas kidney transplantation was available in most countries of the region. Public government funding that makes acute dialysis, chronic HD, chronic PD, and kidney transplantation medications free at the point of delivery was available in 54.5%, 72.7%, 54.5%, and 54.5% of countries, respectively. Conservative kidney management was available in 45% of countries. Only Oman had a CKD registry; 7 countries (64%) had dialysis registries, and 8 (73%) had kidney transplantation registries. The ISN Middle East region has a high burden of kidney disease and multiple challenges to overcome. Prevention and detection of kidney disease can be improved by the design of tailored guidelines, allocation of additional resources, improvement of early detection at all levels of care, and implementation of sustainable health information systems.
Synthesis of pyrazole-fused azepino[5,4,3-cd]indoles Safieh, Kayed A. Abu; El-Abadelah, Mustafa M.; Zarga, Musa H. Abu ...
Journal of heterocyclic chemistry,
May/June 2001, Volume:
38, Issue:
3
Journal Article
Peer reviewed
The synthesis of some new pyrazolo3′,4′:6,7azepino5,4,3‐cd indoles (10a‐c) was achieved via regios‐elective cyclization of the respective 3‐(4‐acylaminopyrazol‐5‐yl)indoles (9a‐c) under ...Bischler‐Napieralski reaction conditions. The latter compounds were obtained by acylation of the corresponding 3‐(4‐aminopyra‐zol‐5‐yl)indoles (8a,b) which, in turn, were prepared by reduction of the 3‐(4‐nitropyrazol‐5‐yl)indoles precursors (7a,b). The latter synthons were accessible from the reaction of indolylzinc chlorides (5a,b) with 5‐chloro‐1,3‐dimethyl‐4‐nitropyrazole. Ms and nmr spectral data of 10a‐c are in agreement with the assigned azepino‐indole structure as determined for 10a by X‐ray crystal measurements which demonstrate that the azepine ring is almost completely planar with the indole and pyrazole rings.
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This study investigates the effect of using water as a low-viscosity component in ternary amine-based deep eutectic solvents (DESs) on the physicochemical properties, thermal stability, and CO2 ...absorption capacity of the resulting DESs. It should be emphasized that water is a component of the ternary DES. The effect of water content in the DES, type of hydrogen bond acceptors (HBAs), hydrogen bond donors (HBDs), and HBA:HBD ratio on the above parameters was investigated. Moreover, the effect of temperature and pressure on the CO2 absorption capacity of DESs was predicted using the predictive model COSMO-RS. This model was also used to predict the CO2 solubility in the DESs and the results were compared with the experimental values. The results showed that the addition of small amounts of water, e.g., 5 and 10 wt% during preparation, can significantly decrease the viscosity of the resulting DESs, up to 25% at room temperature, while maintaining the high CO2 absorption capacity and high thermal stability. The ternary DESs based on MEA exhibited a high CO2 absorption capacity of 0.155-0.170 g CO2 / g DES. The ternary DESs were found to be thermally stable with a decomposition temperature of 125°C, which promotes the use of such solvents in post-combustion capture processes. Finally, COSMO-RS proved to be a suitable tool for qualitative prediction of CO2 solubility in DESs and demonstration of trends related to the effects of temperature, pressure, molar ratio, water content, HBD and HBA on CO2 solubility.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A quantitative assessment of the genotoxicity of silver nanoparticles (AgNPs) ascribed to its transplacental transfer and tissue distribution in pregnant rats was carried out in this study. A single ...intravenous (i.v.) injection of AgNPs with a size range from 4.0 to 17.0 nm was administered to pregnant rats at a dose of 2 mg/kg b.w. on the 19th day of gestation. Five groups beside control, each of the five rats were euthanized after 10 min, 1, 6, 12, or 24 h, respectively. The accumulation of nanoparticles (NPs) in mother and fetal tissues was quantified by inductively coupled plasma optical emission spectroscopy, where the highest accumulation level was recorded in maternal blood (0.523 µg/ml) after 24 h of administration. AgNPs induced accumulation in spleen tissue higher than placenta and fetal tissue homogenates. The data showed significantly detected levels of 8-hydroxydeoxyguanosine in all collected samples from administered animals compared with untreated individuals. Level of 8-OHdG in amniotic fluid exhibited the greatest values followed by maternal spleen, kidneys, and liver, respectively. Investigation by transmission electron microscope showed that the transfer of AgNPs through placental wall caused indentation of nuclei, clumped chromatin, pyknotic nuclei, and focal necrotic areas, while AgNPs appeared mainly accumulated in the macrophages of the spleen. Therefore, the data assume that the genotoxicity studies of AgNPs must be recommended during a comprehensive assessment of the safety of novel types of NPs and nanomaterials. Additionally, exposure to AgNPs must be prevented or minimized during pregnancy or prenatal periods.
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